Re: [xfstests PATCH] generic/567: add partial pages zeroing out case

["Darrick J. Wong" <djwong@kernel.org>]

On Mon, Dec 23, 2024 at 10:39:30AM +0800, Zhang Yi wrote:
> From: Zhang Yi <yi.zhang@huawei.com>
> 
> This addresses a data corruption issue encountered during partial page
> zeroing in ext4 which the block size is smaller than the page size [1].
> Expand this test to include a zeroing range test that spans two partial
> pages to cover this case.
> 
> Link: https://lore.kernel.org/linux-ext4/20241220011637.1157197-2-yi.zhang@huaweicloud.com/ [1]
> Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
> ---
>  tests/generic/567     | 50 +++++++++++++++++++++++++------------------
>  tests/generic/567.out | 18 ++++++++++++++++
>  2 files changed, 47 insertions(+), 21 deletions(-)
> 
> diff --git a/tests/generic/567 b/tests/generic/567
> index fc109d0d..756280e8 100755
> --- a/tests/generic/567
> +++ b/tests/generic/567
> @@ -4,43 +4,51 @@
>  #
>  # FS QA Test No. generic/567
>  #
> -# Test mapped writes against punch-hole to ensure we get the data
> -# correctly written. This can expose data corruption bugs on filesystems
> -# where the block size is smaller than the page size.
> +# Test mapped writes against punch-hole and zero-range to ensure we get
> +# the data correctly written. This can expose data corruption bugs on
> +# filesystems where the block size is smaller than the page size.
>  #
>  # (generic/029 is a similar test but for truncate.)
>  #
>  . ./common/preamble
> -_begin_fstest auto quick rw punch
> +_begin_fstest auto quick rw punch zero
>  
>  # Import common functions.
>  . ./common/filter
>  
>  _require_scratch
>  _require_xfs_io_command "fpunch"
> +_require_xfs_io_command "fzero"

Please don't overload an existing test.  Filesystems such as gfs2,
hugetblfs, nfs, ntfs3, and ocfs2 support fpunch but don't support fzero.
This change opens a testing gap for those filesystems.

--D

>  testfile=$SCRATCH_MNT/testfile
>  
>  _scratch_mkfs > /dev/null 2>&1
>  _scratch_mount
>  
> -# Punch a hole straddling two pages to check that the mapped write after the
> -# hole-punching is correctly handled.
> -
> -$XFS_IO_PROG -t -f \
> --c "pwrite -S 0x58 0 12288" \
> --c "mmap -rw 0 12288" \
> --c "mwrite -S 0x5a 2048 8192" \
> --c "fpunch 2048 8192" \
> --c "mwrite -S 0x59 2048 8192" \
> --c "close"      \
> -$testfile | _filter_xfs_io
> -
> -echo "==== Pre-Remount ==="
> -_hexdump $testfile
> -_scratch_cycle_mount
> -echo "==== Post-Remount =="
> -_hexdump $testfile
> +# Punch a hole and zero out straddling two pages to check that the mapped
> +# write after the hole-punching and range-zeroing are correctly handled.
> +_straddling_test()
> +{
> +	local test_cmd=$1
> +
> +	$XFS_IO_PROG -t -f \
> +		-c "pwrite -S 0x58 0 12288" \
> +		-c "mmap -rw 0 12288" \
> +		-c "mwrite -S 0x5a 2048 8192" \
> +		-c "$test_cmd 2048 8192" \
> +		-c "mwrite -S 0x59 2048 8192" \
> +		-c "close"      \
> +	$testfile | _filter_xfs_io
> +
> +	echo "==== Pre-Remount ==="
> +	_hexdump $testfile
> +	_scratch_cycle_mount
> +	echo "==== Post-Remount =="
> +	_hexdump $testfile
> +}
> +
> +_straddling_test "fpunch"
> +_straddling_test "fzero"
>  
>  status=0
>  exit
> diff --git a/tests/generic/567.out b/tests/generic/567.out
> index 0e826ed3..df89b8f3 100644
> --- a/tests/generic/567.out
> +++ b/tests/generic/567.out
> @@ -17,3 +17,21 @@ XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
>  002800 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58  >XXXXXXXXXXXXXXXX<
>  *
>  003000
> +wrote 12288/12288 bytes at offset 0
> +XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
> +==== Pre-Remount ===
> +000000 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58  >XXXXXXXXXXXXXXXX<
> +*
> +000800 59 59 59 59 59 59 59 59 59 59 59 59 59 59 59 59  >YYYYYYYYYYYYYYYY<
> +*
> +002800 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58  >XXXXXXXXXXXXXXXX<
> +*
> +003000
> +==== Post-Remount ==
> +000000 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58  >XXXXXXXXXXXXXXXX<
> +*
> +000800 59 59 59 59 59 59 59 59 59 59 59 59 59 59 59 59  >YYYYYYYYYYYYYYYY<
> +*
> +002800 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58  >XXXXXXXXXXXXXXXX<
> +*
> +003000
> -- 
> 2.46.1
> 
>